When I changed the speedo out for the one I bought from BlackBird, I took the T out for a quick test run to make sure that the speedo was working right. I also mounted my GPS as well so I had something to compare with. Speed wise I found that the speedo was 1-2 mph faster than the GPS but at 95 mph and no screen, I could barely hold on to the handlebars. I typically get 45 mpg and hit reserve at about 120 miles. All most all of my driving is back and forth to work on the highway and I try to keep it close to 65 mph as I don't need to go any faster - besides, if I hurry to work then I get less time listening to my audiobooks.